water level and water feeder questions

a2shutt

Hi, I've got a couple of questions regarding the water level in my Burham Independence steam boiler (one pipe system).



The system is in a 7 unit apartment building. I had a TON of problems with it when I first bought the building, but this forum basically helped me to get it running the way it should. Thanks again to everyone who helped me 2 years ago!



Anyway, I've got an issue with losing water. I fill the water level up to the top of the sight glass, and usually (depends on the temp ie how much the boiler is running) the water is gone from the sight glass within 2-3 days. Usually more like 3 days. The LWCO will shut the boiler down and as soon as I start adding water it will fire.



So is it normal to be losing this much water? The system generally runs pretty good. No water hammer, no water vapor coming out the chimney, no wet/humid boiler room, no water on the floor, decent pressure, good main line venting, no surging, clean water when I flush the LWCO. Plus I can't seem to find any steam leaks. I fixed several last year, but I don't see any now. There is a half dry/half wet return, but it is not buried in concrete and is relatively new.



If its not normal, could the return be clogged? The only other thing i can think of is that I'm losing steam out a radiator vent in an apartment, but I can't imagine losing that much water that way.



The other issue I've got is that the stupid McDonnell Miller auto feed is not working correctly. I posted last winter about it but never figured out what was wrong. Several times it seemed to get stuck on, and filled the whole system with water until it was coming out of first floor radiator vents. yeah not pretty. I've been adding water manually (maybe a good thing-I noticed the first problem!) but I'm scared that my LWCO will fail some day and I'll have a cracked boiler.



Anyone have ideas for me? thanks!

nicholas bonham-carter

Finding a leak

First, when it has warmed up a bit, overfill the boiler, and let it sit while you look in the firebox, and around the outside along the wet returns for a leak. Check the drain on the LWCO, as it can drip, if the crud in there gets hung up in the (old style spring-loaded valve).If you can attach a tall vertical nipple to the pressure relief tapping, and fill to the top, any drop in level will be easily seen as a drop in that pipe.

In the meantime, alert your tenants that you are looking for a steam leak. How many radiators are there?--NBC

a2shutt

radiators

I should have mentioned that one of the units is on a hot water loop. I think there are two baseboard radiators in there.



In the rest of the building-I'm having to guess as close as I can here-there are 20-22 regular steam radiators. I've replaced the vents on about half of them.

Hap_Hazzard

Did you check the valves?

One common place to lose water (as steam) is the valve stem packings. You'll usually hear hissing or sizzling coming from the valve while the heat is on. You might want to put a list together of suspicious noises to listen for and put this in a newsletter item at the start of every heating season.



20-22 leaky valves can lose a lot of water, but I doubt this is your issue. You probably have a leak. The most common place for a leak is the wet return, but it's often hard to inspect every inch for leaks when sections are buried or embedded in walls, but if you can rule out everything else, you can just bypass these sections and you're done--unless you missed something.



Leaks in black pipe wet returns usually occur at the joints, because the threads cut halfway through the walls of the pipes and create a nice place for moisture to collect, but loose paint, dirt and rust scale can also harbor moisture. If the returns are uninsulated and left filled during the summer, condensation can accumulate on the outside and attack the pipes--yes, wet returns usually rust out from the outside in!



If you know where the joints are (wherever the return makes a bend and usually at 10' intervals on straight runs), you can focus on these. If the pipe runs behind drywall an inspection camera or borescope can be inserted either through an electrical box or a small inspection hole you can easily patch. Also pull back carpet and look for wet drywall footings. Have any tenants recently reported black mold problems or musty smells?

Hap_Hazzard

LWCO and water feeder

I agree that you're lucky that the water feeder didn't mask the water loss issue. This is why we repeatedly caution people about monitoring autofeeder makeup volume.



I should point out that you should not be allowing the water level to repeatedly get so low that the LWCO cuts out. Boilers are happiest with the water level right at the normal water line. A low water level changes the heat distribution pattern in the vessel, and because heat causes the cast iron to expand, stresses are being created in the section walls in places that weren't designed to accommodate it. These repeated changes in internal stress patterns can cause metal fatigue that can lead to outright failure or deformation sufficient to cause a sectional seal to fail. This is why, as Steamhead has pointed out time and again, a fluctuating water level is the leading cause of failure in cast iron sectional boilers. Try to keep the water level as consistent as possible until you have found and remedied the water loss issue.



To address your concerns about dry-firing, you might want to consider a secondary probe-type LWCO and/or a different automatic water-feeder. The secondary LWCO would be installed at a tapping slightly below the main LWCO, so it will cut the burner if a primary LWCO failure allows the water level to fall to that point. Either or both of the LWCOs could be wired up to activate the water feeder and/or sound an alarm. Typically, secondary LWCOs are configured to require a manual reset. There are many possibilities, but consult your local code to see what, if any, restrictions or requirements exist pertaining to the use of these devices.



Another possible anti-flooding measure would be to install a second solenoid valve in the water feed line. The field coils of the two solenoids should be wired in parallel, but the valves should be plumbed in series, so when the water-feeder is activated it will open both valves and allow the water to flow. When the LWCO is satisfied, both valves should close, but even if one of them fails, the other one should, unless something pretty unlikely happens, shut off the water. These solenoid-actuated valves are made by NEMA. They also use them in industrial pressure washers and coin-operated car wash machines. Any place that sells replacement parts for this kind of equipment should carry them. Just be sure to get one with the right field coil voltage (120 or 24), and, again, check your local codes to make sure this is kosher.



Also, since most of these valve failures happen as a result of seat contamination, it wouldn't be a bad idea to put a cartridge filter in the line upstream. Again, consult your codes, but basically, anything that might prevent the feeder from filling the boiler will keep the LWCO from being satisfied, so you won't end up dry-firing because a filter got plugged up or a secondary valve failed to open.

a2shutt

valves

I have re-packed several (maybe 6-8) valves when I've noticed them leaking. I'm thinking I should do a walk-thru of all the units. Even then, I have a hard time seeing that much water being lost thru valve packings. Maybe I'm wrong.



Its a 1 pipe system, so the returns are all in the basement and readily accessible. Someone formed and poured a nice concrete trench that the wet return runs down, so it is pretty easy to inspect. I have made a habit of flushing it (there is a valve at each end) and there seems to be decent water flow. I'll inspect the entire length of the return. The returns are uninsulated, and yes, they are half full all summer long.



Tenants haven't complained about anything except when the boiler shuts down and it gets chilly. The company that managed it before me made a habit of ignoring them, so they are conditioned to not call me. Sometimes nice, sometimes not.

a2shutt

lwco

There already is a secondary (probe) lwco with a manual reset. It has not been tripped, so it has been the float lwco shutting things down.



Do you think it is likely that the reason the water feeder was flooding the whole system was because of the valves not seating properly? If this is the case, then simply replacing the valve should solve it, right?



Obviously I need to find this leak, but it would be nice if the water feeder actually worked.



Right now I have just pulled the cover off the water feed and unhooked a couple of wires to keep it from running.

Hap_Hazzard

Fixing the water feeder.

Yes. Replacing the valve will fix the feeder. For now. But, if something got in there, it can happen again, and, as you are painfully aware, the consequences are not very nice. This is one place where the manufacturers of these devices have really fallen down. They focus so much on safety that they seem oblivious to the seriousness of boiler flooding. Sure, probably no one has ever been killed by a flooded boiler, and it's of the utmost importance to protect human life--we all get that--but boiler flooding can and does cause thousands upon thousands of dollars in property damage. How have the manufacturers addressed this? By putting a notice in the warranty disclaiming any responsibility for such damages. Great. So they're covered, but what about us?



At some point I'd think they would realize that, if people lose their shirts a couple of times they will stop using these things. That's not just bad for business, but all the benefits they might have provided by protecting life and property are out the window too.



At the same time, I think there's also some blame to be laid at the feet of the consumers and even some of the professional plumbers and heating contractors who install these devices. While the leading cause of valve failure is seat contamination, the ultimate reason these devices fail is that they are being misused.



The product literature makes it pretty clear, if you read it, that these are safety--not convenience--devices, but I can't tell you how many times I've read posts from people who say they installed them because they were too lazy to keep going down to the basement to top up their boilers. Seriously. This is like the people who take batteries out of smoke detectors because they're tired of having them go off all the time.



Water does not constantly leak out of a healthy system. If you install a water feeder you should put a meter on it and hope to god it never reads anything other than "0." That means MR. Couch Potato has to get off his butt and go down to his basement and read that thing every day! And if it ever reads anything other than "0," be concerned. Something is wrong.



So, activation of a water feeder means a safety device has prevented a bad situation--water loss--from becoming worse--a no-heat condition. It is not a routine event. If it is treated like a routine event, it will happen routinely, and when it happens routinely, pretty soon a piece of sand or limescale is going to get stuck in the seat when the valve snaps shut, and in a matter of hours water will be seeking its lowest level all over somebody's living room because somebody asked a valve that should only open and close in an emergency to open and close, open and close, open and close over and over on a daily basis. That's just asking for trouble, and boy can these things deliver trouble if you ask for it.

a2shutt

ok

makes sense to me. thanks for the explanation. I'll see about replacing that valve and do some more in depth digging for leaks. thanks again.

a2shutt

did some poking around today

I inspected all of the steam lines in the basement. no leaks. checked the wet return. no leaks. (that I could see)



removed the side cover on the boiler, no water visible.



I've had to fix a few steam leaks, and they were generally pretty obvious. Lots of steam, dripping water, soggy insulation...no sign of any of that.



So-I've either got leaking valve stems/radiator vents, or a boiler vessel crack. Right? Or am I missing something?



I'll be inspecting all the radiators over the next few days to see if there are any obvious leaks.



BUT-today (probably around zero degrees outside) I did see some white smoke from the chimney. I haven't noticed it before. That being said, though, all the chimneys I could see on surrounding buildings had white smoke, too. It is a gas boiler.



I'd be shocked if it had gone bad already-its a Burnham Independence installed in 07. And not sure what I would do.



How can I tell if there is a crack in the boiler itself? The white smoke thing seems kind of subjective. Does overfilling it always reveal those leaks? (Haven't overfilled it yet). Should there be water on the inside of the chimney if I look in the clean out door at the bottom?

JStar

Boiler

Definitely overfill the boiler and keep an eye inside the burner box, as well as around the boiler. Those Burnham's have been known to leak at an early age. Usually in the back corners above the water line.



White smoke out of the chimney is typically normal during these extreme cold temperatures.

Dean_7

Water feeder

 I'm just a homeowner butJstar is right this is a picture of my old Burnham Independence 4PVwhich rotted out and started leaking at 8 years old. The first sign was the water feeder was cycling on every day when before  it came on maybe once a season. This is the outside section where the gauge glass, controls and LWCO connect. And you might want to consider installing a hydrolevel feeder which displays the amount of water it feeds.

a2shutt

today

i stopped in to do some more leak hunting. when i arrived, there was the old plume of white smoke out the chimney. When i got inside, though, i realized the boiler wasn't even running. that smoke was just exhaust gasses from the water heaters. when the boiler kicked on later, the smoke was visibly more, but not more than would be expected when you consider the water heaters.



i also filled the boiler until i had a good stream coming out of the skim port. im not sure that was enough to find above-waterline leaks, but i was nervous about adding too much cold water to a hot boiler. i let it sit for a while with no visible drips inside the housing. that may not mean anything though.



one possibility presented itself today-wondering what others think. I have a backflow preventer that has been dripping a bit-not sure if it is working properly or not. Could the lost water from the boiler possibly be backflowing into the water system? It could easily lose 2-3 gallons and with the amount of water usage in the building i'm not sure anyone would notice a little sediment in the water.



in any case, i did shut the valves on both sides of the backflow preventer. we'll see if that helps the water loss.

a2shutt

with the cost

of a new boiler, how can anyone be ok with some of these short lifespans? I mean, shouldn't a several thousand dollar unit last more than a few years?!

Hap_Hazzard

Backflow preventer and white smoke

Yes, the backflow preventer could be where you're losing water, and it's probably piped to a drain so you wouldn't see it unless you looked.



Don't be alarmed by any vapor plumes you see in this weather. The air is simply too cold to hold any moisture, so the vapor practically turns to snow right out of the stack.

Dean_7

Cost

No one should be ok with these short lifespans. I personally don't expect anything new to last the 70+ years the boiler the Burnham replaced lasted. But with the cost of these units at several thosand dollars each plus the cost of installation they shouldn't be leaking and failing after a few years. A reasonable expectation would be about 20 year lifespan, And if you ask the manufacturers they will say it isn't their fault, it's the water. Which may be true in some cases because if given enough time water will dissolve a battleship. However this should be taken into account and designed for accordingly.

BobC

Not high enough

You stated you filled the boiler till water was coming out of the skim port at a good rate, that is not high enough.You have to fill that boiler till the water is well above the top of the sight glass. If it takes 20 seconds to fill it to the top of the sight glass give it 15-20 seconds more, Then let it sit for 20-30 minutes and inspect inside and outside of the boiler for leaks.



When your done, drain it down to the normal water line and fire it up to make steam to drive off any oxygen in the water.



Bob